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1. A note on entanglement entropy and topological defects in symmetric orbifold CFTs

   https://doi.org/10.1007/JHEP09(2024)010  

   Gutperle, Michael; Li, Yan-Yan; Rathore, Dikshant; Roumpedakis, Konstantinos (September 2024, Journal of High Energy Physics)

   A<sc>bstract</sc> In this brief note we calculate the entanglement entropy inM^⊗N/S_Nsymmetric orbifold CFTs in the presence of topological defects, which were recently constructed in [1, 2]. We consider both universal defects which realizeRep(S_N) non-invertible symmetry and non-universal defects. We calculate the sub-leading defect entropy/g-factor for defects at the boundary of the entangling surface as well as inside it. 

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2. Notes on a surface defect in the O(N) model

   https://doi.org/10.1007/JHEP12(2023)004  

   Giombi, Simone; Liu, Bowei (December 2023, Journal of High Energy Physics)

   A<sc>bstract</sc> We study a surface defect in the free and criticalO(N) vector models, defined by adding a quadratic perturbation localized on a two-dimensional subspace of thed-dimensional CFT. We compute the beta function for the corresponding defect renormalization group (RG) flow, and provide evidence that at long distances the system flows to a nontrivial defect conformal field theory (DCFT). We use epsilon and largeNexpansions to compute several physical quantities in the DCFT, finding agreement across different expansion methods. We also compute the defect free energy, and check consistency with the so-calledb-theorem for RG flows on surface defects. 

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3. A cluster of results on amplituhedron tiles

   https://doi.org/10.1007/s11005-024-01854-4  

   Even-Zohar, Chaim; Lakrec, Tsviqa; Parisi, Matteo; Sherman-Bennett, Melissa; Tessler, Ran; Williams, Lauren (September 2024, Letters in Mathematical Physics)

   Abstract The amplituhedron is a mathematical object which was introduced to provide a geometric origin of scattering amplitudes in$$\mathcal {N}=4$$ $N=4$super Yang–Mills theory. It generalizescyclic polytopesand thepositive Grassmannianand has a very rich combinatorics with connections to cluster algebras. In this article, we provide a series of results about tiles and tilings of the$$m=4$$ $m=4$amplituhedron. Firstly, we provide a full characterization of facets of BCFW tiles in terms of cluster variables for$$\text{ Gr}_{4,n}$$ ${\text{Gr}}_{4,n}$. Secondly, we exhibit a tiling of the$$m=4$$ $m=4$amplituhedron which involves a tile which does not come from the BCFW recurrence—thespuriontile, which also satisfies all cluster properties. Finally, strengthening the connection with cluster algebras, we show that each standard BCFW tile is the positive part of a cluster variety, which allows us to compute the canonical form of each such tile explicitly in terms of cluster variables for$$\text{ Gr}_{4,n}$$ ${\text{Gr}}_{4,n}$. This paper is a companion to our previous paper “Cluster algebras and tilings for the$$m=4$$ $m=4$amplituhedron.” 

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4. Natural and Experimental Constraints on a Flow Law for Dislocation‐Dominated Creep in Wet Quartz

   https://doi.org/10.1029/2020JB021302  

   Lusk, Alexander D. J.; Platt, John P.; Platt, Jason A. (May 2021, Journal of Geophysical Research: Solid Earth)

   Abstract We present a flow law for dislocation‐dominated creep in wet quartz derived from compiled experimental and field‐based rheological data. By integrating the field‐based data, including independently calculated strain rates, deformation temperatures, pressures, and differential stresses, we add constraints for dislocation‐dominated creep at conditions unattainable in quartz deformation experiments. A Markov Chain Monte Carlo (MCMC) statistical analysis computes internally consistent parameters for the generalized flow law: = Aσⁿe^−(Q+VP)/RT. From this initial analysis, we identify differenteffectivestress exponents for quartz deformed at confining pressures above and below ∼700 MPa. To minimize the possible effect of confining pressure, compiled data are separated into “low‐pressure” (<560 MPa) and “high‐pressure” (700–1,600 MPa) groups and reanalyzed using the MCMC approach. The “low‐pressure” data set, which is most applicable at midcrustal to lower‐crustal confining pressures, yields the following parameters: log(A) = −9.30 ± 0.66 MPa^−n−r s⁻¹;n = 3.5 ± 0.2;r = 0.49 ± 0.13;Q = 118 ± 5 kJ mol⁻¹; andV = 2.59 ± 2.45 cm³ mol⁻¹. The “high‐pressure” data set produces a different set of parameters: log(A) = −7.90 ± 0.34 MPa^−n−r s⁻¹;n = 2.0 ± 0.1;r = 0.49 ± 0.13;Q = 77 ± 8 kJ mol⁻¹; andV = 2.59 ± 2.45 cm³ mol⁻¹. Predicted quartz rheology is compared to other flow laws for dislocation creep; the calibrations presented in this study predict faster strain rates under geological conditions by more than 1 order of magnitude. The change innat high confining pressure may result from an increase in the activity of grain size sensitive creep. 

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5. Mapping Evidence on the Burden of Breast, Cervical, and Prostate Cancers in Sub-Saharan Africa: A Scoping Review

   https://doi.org/10.3389/fpubh.2022.908302  

   Musekiwa, Alfred; Moyo, Maureen; Mohammed, Mohanad; Matsena-Zingoni, Zvifadzo; Twabi, Halima Sumayya; Batidzirai, Jesca Mercy; Singini, Geoffrey Chiyuzga; Kgarosi, Kabelo; Mchunu, Nobuhle; Nevhungoni, Portia; et al (June 2022, Frontiers in Public Health)

   BackgroundCancer remains a major public health problem, especially in Sub-Saharan Africa (SSA) where the provision of health care is poor. This scoping review mapped evidence in the literature regarding the burden of cervical, breast and prostate cancers in SSA. MethodsWe conducted this scoping review using the Arksey and O'Malley framework, with five steps: identifying the research question; searching for relevant studies; selecting studies; charting the data; and collating, summarizing, and reporting the data. We performed all the steps independently and resolved disagreements through discussion. We used Endnote software to manage references and the Rayyan software to screen studies. ResultsWe found 138 studies that met our inclusion criteria from 2,751 studies identified through the electronic databases. The majority were retrospective studies of mostly registries and patient files (n= 77, 55.8%), followed by cross-sectional studies (n= 51, 36.9%). We included studies published from 1990 to 2021, with a sharp increase from 2010 to 2021. The quality of studies was overall satisfactory. Most studies were done in South Africa (n= 20) and Nigeria (n= 17). The majority were on cervical cancer (n= 93, 67.4%), followed by breast cancer (67, 48.6%) and the least were on prostate cancer (48, 34.8%). Concerning the burden of cancer, most reported prevalence and incidence. We also found a few studies investigating mortality, disability-adjusted life years (DALYs), and years of life lost (YLL). ConclusionsWe found many retrospective record review cross-sectional studies, mainly in South Africa and Nigeria, reporting the prevalence and incidence of cervical, breast and prostate cancer in SSA. There were a few systematic and scoping reviews. There is a scarcity of cervical, breast and prostate cancer burden studies in several SSA countries. The findings in this study can inform policy on improving the public health systems and therefore reduce cancer incidence and mortality in SSA. 

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